In refrigeration compressors the affinity between refrigerant and lubricant generally requires separation of oil from the discharged refrigerant and its return to the compressor. Additionally, the returned oil is normally filtered before being supplied to the oil distribution structure. Because the filter must be accessible for replacement as well as isolatable to minimize oil loss, it is located external to the compressor. This, however, requires brazed lines downstream of the filter and this can result in debris being carried to the bearings, etc.